mikmei

Sorry, I just found this solution in the forum:
.site-content .entry-header,
.site-content .entry-content,
.site-content .entry-summary,
.site-content .entry-meta,
.page-content {
max-width: 800px;
}
I obviously wrote 1070px instead of 800. It didn’t say where to put this coding (or if one was supposed to replace the coding somewhere) but I put it in Appearance-Edit CSS under the welcome text that was already there. It worked!

I found the solution on this site:
https://thegeekgirl.net/how_to/design-your-site/twenty-eleven-wordpress-theme
The method to remove horizontal lines applied to my theme as well (I have changed theme to Moka now for a number of reasons but it also had some lines I needed to remove). The site is really great for those of us who are not programmers by occupation. Easy instructions and explanations.